Chicken pox (or varicella for its medical name) is caused by a herpes virus and, although usually mild, it is incredibly infectious, being passed around through coughs and sneezes.
Once your child has had chicken pox, they areunlikelyto get it again. However, the virus remains in the body and can reappear (perhaps during periods of being run down) in adulthood as shingles. Children who have not yet had chicken pox can catch it from an adult with shingles.
Your child will have caught chicken pox long before they show any symptoms - in fact, it might take as long as three weeks for it to become apparent they have the virus.
Your child will have caught chickenpox long before they develop the telltale rash (picture posed by models)
At first, they are likely to get a fever (over 38°C), flu-like aches and pains and perhaps feel a bit sick and go off their food.
The first obvious sign chicken pox is the culprit will be red spots on their face, and these will soon spread down their body to their chest and tummy, back and limbs. Some children are lucky and get relatively few spots; others will have hundreds. Either way, the spots – which will blister and become intensely itchy – can appear everywhere, including on the scalp, soles of the feet and genitals, and even inside the mouth and ears.
After several days, the spots will begin to crust over and start drying out. Eventually, the crusted skin will fall off of its own accord, but new spots will keep forming for up to five days, so the whole process can take between one and two weeks.
It's worth noting that children remain infectious until the very last spot has crusted over – and schools and nurseries are likely to request your child is kept at home until that time.
What can I do?
Because it is caused by a virus, antibiotics will do nothing to get rid of chicken pox, so you just have to ride it out. If you don't feel sure that what your child has is chicken pox, take them to your GP who will confirm it for you.
To help with your child's fever and aches and pains, you can give them the correct dose of liquid paracetamol. If their fever goes above what is considered safe seek medical advice, and if you suspect your newborn has chickenpox, take them to the doctor straight away.
Never give aspirin to a child with chickenpox - as there is a risk they could develop a potentially fatal condition called Reye's syndrome.
Don't be overly worried if your child is off their food for a few days, just be sure to encourage fluid intake to avoid dehydration, which all children - especially little ones - are at risk of when they are poorly.
Now, as for that itching. If you remember having chicken pox yourself as a child, you'll probably also remember how very infuriating it was when your mum told you repeatedly not to scratch or you'd scar yourself for life. She was right, as it goes.
Scratching can cause some scarring - it can also cause the skin to become infected. Cutting fingernails nice and short is a good idea and some cotton gloves, which you should be able to get from your doctor or pharmacy can help with this, too.
You should also get a bottle of calamine lotion, and dab it on to the spots to cool the skin and reduce the itchiness. If your child is really suffering, and the itching is stopping them from sleeping at night, your GP might prescribe some liquid antihistamine (you can also buy this at the chemist for children over a year old). It will reduce the intensity of the itching and can also have a sedative effect, making it easier for your child to get some proper rest at night time.
Other than that, a good distraction can work wonders with toddlers and older children. Once they are past the stage of feeling really poorly, rather than the TV, find things for them to do that engage their hands, such as jigsaws and drawing.
What else could it be?
If your child has a fever and red spots that seems to be clustered around their mouth, hands and feed, they might have hand, foot and mouth disease.
When to see a doctor.
Contact your GP straight away if the blisters on your child's skin become infected or if your child has a pain in their chest or has difficulty breathing.
If your newborn baby is exposed to the chickenpox virus or develops chickenpox symptoms seek medical advice straight away.
For more information on chicken pox symptoms and treatment, visit the NHS Choices website.